<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0px;
            padding: 0px;
        }
        /* .box1{
            width: auto;    不写，或者auto就是自适应
            width: 100px;
            height: 100px;
            padding-left: 100px;
            background-color: yellow;
        } */
        /*
        导航栏
        通栏布局        
        */
        .header,.footer{
            width: 100%;
            height: 50px;
            background-color: yellow;

        }
        .body{
            /* height: 500px; */
            min-height: 500px;
            background-color: red;
        }

        li{
            height: 100px;
        }

        /* 
        min-height/width;
        max-height/width;
        */
    </style>
</head>
<body>
    <!-- <div class="box1"></div> -->
    <div class="header"></div>
    <div class="body">
        <ul>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
            <li>1111111</li>
        </ul>
    </div>
    <div class="footer"></div>
</body>
</html>